Mont. Code § 75-10-626
For the proceeds of bonds or notes authorized by this part, the board of examiners and the department of environmental quality may enter into an agreement under the terms of which the department shall pay the state treasurer, for deposit in accordance with 17-2-101 through 17-2-107, as determined by the state treasurer, an amount sufficient to pay the principal and interest as due on the bonds or notes and to accumulate and maintain reserves as may be required under the bonds. The agreement must further provide that income from the investment of bond proceeds and the reserves not required for the purposes presented in 75-10-625 must be credited against the department's payment obligation. The agreement must also allow for the accumulation of reserves during the first year that the bonds are outstanding, if required. Payments by the department must be made from available funds.
§ 75-10-626, MCA